First report of Pseudopestalotiopsis camelliae-sinensis causing Cunninghamia lanceolata needle blight in China

Cunninghamia lanceolata is an important economic and afforestation tree species in southern China and is widely cultivated in Guizhou (Wu et al, 2025). In October 2025, a needle blight observed on C. lanceolata in Taijiang County, with an incidence rate 65% (130 of 200 plants). Symptoms initially yellow spots appear on the needles, later, they turn brown and spread throughout the entire branch, leading to the tree's death. Symptomatic needles (n=30) were collected and surface disinfected with 75% ethanol for 15 s, 1% NaClO for 1 minute, rinsed three times with sterile water, air-dried, placed on potato dextrose agar (PDA), and incubated at 25 °C for 5 days. Fungal colonies on PDA of three similar obtained isolates were white, The reverse was white and gradually turned light brown, and dark brown to black conidiomata were irregularly scattered. Conidia were fusiform, straight to slightly curved, five-celled, and measured 26.43 to 27.51 × 5.29 to 5.61 μm (n=20). The three median cells were pigmented with the dark greenish brown. The apical and basal cells were hyaline and generally conical, with two to three apical appendages (17.2~37.13 μm, n=20) and a single basal appendage (2.57~8.76 µm, n=20). Based on morphological and morphological characteristics were similar to Pseudopestalotiopsis species (Maharachchikumbura et al. 2014). DNA of the isolates SHAN1, SHAN2 and SHAN3 were extracted. The rDNA internal transcribed spacer (ITS), translation elongation factor 1-α (TEF-1α), β-tubulin(TUB2) and large subunit (LSU) were amplified with the primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF-2R (Carbone and Kohn 1999), Bt2a/Bt2b (Glass and Donaldson 1995) and LR0R/LR5 (Vilgalys and Hester 1990). The sequences of ITS, TUB2, TEF-1α and LSU were deposited in GenBank (SHAN1: PZ711352, PZ717424, PZ717427 and PZ711417; SHAN2: PZ711353, PZ717425, PZ717428 and PZ711418; SHAN3: PZ711354, PZ717426, PZ717429 and PZ711419). A phylogenetic tree was constructed from the concatenated sequence dataset, and isolate SHAN1, SHAN2 and SHAN3 clustered with Pseudopestalotiopsis camelliae-sinensis with 91% bootstrap support. Based on morphological and molecular analyses, the causal agent was identified as P. camelliae-sinensis. Pathogenicity tests were conducted by inoculating detached healthy branches and two-year-old potted seedlings of C. lanceolata with a conidial suspension (1 × 10⁶ spores/ mL. Each treatment comprised three independent biological replicates, with each replicate containing three detached branches and three seedlings, resulting in a total of nine branches and nine seedlings per treatment. Control materials were sprayed with an equal volume of sterile distilled water. Inoculated tissues were maintained at 25°C under relative humidity 80%. At 7 days post-inoculation, pale yellow to light brown lesions appeared on the needles. By 14 days post-inoculation, the needles had become necrotic and yellowed, exhibiting symptoms similar to those observed in the field, whereas the control plants remained asymptomatic. The fungus was reisolated from all symptomatic needles and confirmed as P. camelliae-sinensis by morphology and multi-locus sequencing (ITS, TUB2, EF1-α and LSU), fulfilling Koch’s postulates. Then P. camelliae-sinensis caused grey blight disease of tea (Shahriar et al, 2022; Wen et al, 2018). To our knowledge, this is the first report of P. camelliae-sinensis causing C. lanceolata in China. This report will provide a reference for the prevention and control of this disease of P. camelliae-sinensis.